Work on the controversial "Poohaven" sewage plant will get underway within days after a High Court judge threw out the case brought by opponents.

The legal bid heard in London on Wednesday was the last resort of campaigners who have spent more than five years fighting plans for the £300million Southern Water facility at Lower Hoddern Farm, Peacehaven.

The water firm will be free to start work next week unless opponents can find grounds to appeal the High Court decision within six days.

Politician Simon Burgess, who has been a prominent supporter of the campaign, yesterday conceded the legal options were limited.

He said: "There's not much grounds for appeal but everyone will go over in their minds what they can do now."

The plant has been jointly planned by Southern Water and East Sussex County Council to deal with waste water from a large area of the county and Brighton and Hove.

Opponents, led by a campaign group called Peacehaven Residents Opposing Urban Development (PROUD), have argued the plant will be too close to a residential area and will emit odours that will negatively affect people.

At the High Court they cited the example of another Southern Water sewage works at Pebsham, near Bexhill, which has failed to meet the council odour controls on several occasions.

They said the situation at Peacehaven would be worse because the plant would be closer to homes.

The judge at the preliminary hearing ruled there was insufficient evidence to take the matter to a full Judicial Review.

PROUD co-ordinator John Hodgson said: "We are still hopeful we can stop this, never say die. We have brought it this far and we intend to take it as far as we can.

"We will have a meeting with our legal team in the next few days and decide what we will do from there."

Southern Water said it was keen to start work as soon as possible.

A spokeswoman said: "We note the decision and remain committed to working with the local community on this project and bringing unprecedented environmental improvements to this important stretch of the south coast."

An East Sussex County Council spokesman said: "We are pleased that the county council's procedures and decision have been vindicated by the court."

Mr Burgess, Labour's prospective parliamentary candidate for the Brighton Kemptown constituency which includes Peacehaven, said the campaigners’ efforts had been remarkable.

He said: "The Peacehaven community has showed what it is capable of. Developers will think twice about taking them on again."